I keep your picture on the wall; it hides a nasty stain that's lying there

Is there a set of necessary and sufficient conditions for deciding to engage in a sexual relationship? How do I know when that set of conditions is met?

I was rolling around the subject of my sexual ethics and I believe that I have obtained a better handle on identifying my moral premises on the topic:

Ethical statemeent: I will only engage in a sexual relationship with someone if I believe that I can trust them with my life, and moreover, the lives of my children, actual or potential, and if I believe that my partner believes the same with respect to me.

Does that sum things up for me? Does that work? It is possible that the statement, as it stands, represents a necessary set of conditions, but do these conditions constitute a sufficient set? I note that, as I understood this statement at the time, it would not have excluded the choice of Crystal at the time I chose her.

Why?

I believed that I trusted her with my life and with the lives of my children. The ethical premise is sound but in applying it to Crystal I made a mistake: as she was, and to many extents, still is, the decision to trust her with the lives of my children or potential children was not sound. Neither of us had the self-knowledge that would have enabled us to furnish and sustain the high-quality nurturing environment necessary to the ultimate well-being of our children, however much I did not understand this at the time.

Why?

Certain key areas of Crystal's integrity were, even in my estimation, even then, very much open to doubt. What was not factored in properly was an understanding that these limits logically implied that together we would be unable to provide such an environment as I desired, and for which I was morally obligated to provide consequent to taking Crystal as my mate and having and raising children with her. I could not trust her, both for limitations of my own and hers. Therefore, the decision to have sex with her was unwarranted, in retrospect.

So, why did I believe it at the time? Why did her prior infidelity and sexual and procreational risk-taking not matter to, or not weigh decisively in, my decision at the time?

I believe that the answer is that I grew up swimming in an ocean of lies. The perceptions of reality with which my immature brain formed the premises about the importance of honesty, and the consequences of dishonesty, were distorted by the environment provided by my parents. Before I was married, did I ever confront Crystal over what I perceived to be her infidelity? No. In fact, was I clear about my boundaries in this regard? No. In fact, I sometimes evaded the importance of my feelings with respect to her behavior. As a matter of fact, I sometimes evaded, to myself, the knowledge of the likelihood that she was cheating on me when in fact she was doing so. Is that true, or was I using the fact that we had no formal, or at least well-understood, agreement between the two of us, to absolve her of the moral responsibility to be "faithful?" I had a standard, but in the absence of communicating it to Crystal and having it clear to both of us, did that allow me to somehow have my cake and eat it too?

In what way? To what end?

Did I need to be able to pretend that she loved me and that she cared? It is possible that I thought so. If it is so, this would explain why I was frequently in doubt about what she felt for me. I need to ruminate on that. Perhaps this would be a good thing to look up in previous journaling.